\Rpn\Services\Onv\Models\OnvForm\EmissionsStationarySource::select("onvos_request_emissions_stationary_sources.*")
            ->join('onvs', function ($join) {
                $join->on('onvs.service_request_id', '=', 'onvos_request_emissions_stationary_sources.service_request_id');
            })
            ->whereNotNull('geometry')
            ->chunk(1000, function ($stationaries) {
                \DB::transaction(function () use ($stationaries) {
                    $layer = \Rpn\Services\Map\Models\MapLayer::MAP_LAYER_STATIONARY;
                    $type = \Rpn\Services\Onv\Models\OnvForm\EmissionsStationarySource::class;
                    /** @var \Rpn\Services\Onv\Models\OnvForm\EmissionsStationarySource $stationary */
                    foreach ($stationaries as $stationary) {
                        $id = $stationary->id;

                        if (empty($stationary->geometry)) {
                            continue;
                        }

                        $geo = json_encode($stationary->geometry);

                        try {
                            $point = \GeoJson\GeoJson::jsonUnserialize($stationary->geometry);
                        } catch (\Throwable $e) {
                            continue;
                        }

                        \DB::statement("
                            insert into map_objects(map_layer_id, model_type, model_id, geometry, created_at, updated_at)
                            values(${layer}, '${type}', ${id}, ST_MakeValid(ST_GeomFromGeoJSON('${geo}')), now(), now())
                            on conflict do nothing;
                        ");
                    }
                });
            });

接下来的代码给了我一个内存限制错误（允许的内存大小 2147483648 字节已耗尽）。尽管我使用的是光标和块，为什么它会以这种方式工作？我该如何修复它？